Visualization Materials Using Silicon-Based Optical Nanodisks (ViSiON) for Enhanced Nir Imaging in Ophthalmology.

We present ViSiON (Visualization materials composed of Silicon-based Optical Nanodisks), which offers a unique optical combination of near-infrared (NIR) optical properties and biodegradability. Initially, we conducted numerical simulations to calculate the total extinction and scattering effects of ViSiON by the diameter-to-thickness ratio, predicting precise control over its scattering properties in the NIR region. A top-down patterning technique was employed to synthesize ViSiON with accurate diameter and thickness control. ViSiON with a 50 nm thickness exhibited scattering properties over 400 times higher than that of 30 nm, rendering it suitable as a contrast agent for optical coherence tomography (OCT), especially in ophthalmic applications. Furthermore, ViSiON possesses inherent biodegradability in media, with approximately 95% degradation occurring after 48 hours, and the degradation rate can be finely tuned based on the quantity of protein coating applied to the surface. Subsequently, we validated the OCT imaging capability even within vessels smaller than 300 μm, simulating retinal vasculature using a retinal phantom. Then using an ex ovo chick embryo model, we demonstrated that ViSiON enhances the strength of protein membranes by 6.17 times, thereby presenting the potential for ViSiON as an OCT imaging probe capable of diagnosing retinal diseases. This article is protected by copyright. All rights reserved.